Added diff states (no binary serialization, no static typing) - includes fix for the first-state problem.

[TheYellowArchitect]

All states are sent UNRELIABLE_ORDERED regardless if they are a full state (contains all properties) or a diff state (contains only the properties with new values) Once the client receives any state, he sends a RELIABLE rpc to the server that he has indeed received a full state, and so it can start receiving diff states. Once this RELIABLE rpc is received by the server, all future states sent to that specific peer are diff states, instead of full states. Diff states are states whose property/values included are only those which have changed from the previous tick.

This implementation also solves the diff states problem mentioned in #264 (this is the 2nd way, and I think its the cleanest and most performant)

I have tested it and found no issues.

Solves #157 As for the bandwidth it saves, see forest-brawl example: "Displaceable:mass", "Displaceable:impulse", ":speed" which change only once via powerup, so 3/5 states are skipped with diff states. Assuming the variables were of same size, with diff states, there is 60% less bandwidth.

Requires #277 which is just static typing additions (so this PR is easy to read, instead of having double the size)